Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (19,088)	$ (13,159)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	308	221
Loss on disposal of fixed assets	0	3
Interest expense	0	4
Non-cash consideration for licensing and collaboration revenue	(128)	0
Change in fair value of equity securities	88	0
Stock-based compensation expense	3,024	343
Change in fair value of MSKCC success payments liability	(1,596)	686
Amortization of investment premiums	327	0
Non-cash lease expense	500	0
Changes in operating assets and liabilities:
Accounts receivable	779	74
Contract assets	(6)	355
Other receivables	1,313	(1,095)
Prepaid expenses and other current assets	(1,296)	(562)
Other assets	(487)	(421)
Accounts payable	(1,915)	37
Accrued expenses and other current liabilities	(2,831)	3,879
Deferred revenue, current and long-term	(572)	29,964
Deferred rent and lease incentive liability	0	(8)
Operating lease liabilities	(85)	0
Other liabilities	(8)	(8)
Net cash provided by (used in) operating activities	(21,673)	20,313
CASH FLOWS FROM INVESTING ACTIVITIES:
Maturities of marketable securities	39,300	0
Purchases of property and equipment	(723)	(22)
Purchases of marketable securities	(110,684)	0
Net cash used in investing activities	(72,107)	(22)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of Series C convertible preferred stock, net of issuance costs	0	109,235
Proceeds from exercise of stock options and purchases of common stock under employee stock purchase plan	990	564
Payments on capital lease	0	(119)
Net cash provided by financing activities	990	109,680
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	(92,790)	129,971
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH - BEGINNING OF PERIOD	240,466	15,953
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH - END OF PERIOD	147,676	145,924
RECONCILIATION OF CASH, CASH EQUIVALENTS, AND RESTRICTED CASH
Cash and cash equivalents	147,630	145,924
Restricted Cash	46	0
CASH. CASH EQUIVALENTS, AND RESTRICTED CASH ON THE BALANCE SHEET	147,676	145,924
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for income taxes	0	0
Cash paid for interest	0	1
SUPPLEMENTAL SCHEDULE OF NON-CASH INVESTING AND FINANCING ACTIVITES:
Acquisition of property and equipment included in accrued expenses and other current liabilities	981	95
Deferred issuance costs related to initial public offering unpaid at period end	0	422
Series C convertible preferred stock issuance costs unpaid at period end	0	408
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 26,249	$ 0